Continuous flow multiple tank fuel system



Sept. 30, 1952 D. SAMIRAN 2,612,216

CONTINUOUS FLOW MULTIPLE TANK FUEL SYSTEM Original Filed Aug. 1, 1945 2SHEETS-SHEET l Sept. 30, 1952 D. SAMIRAN 2,612,216

CONTINUOUSYFLOW MULTIPLE TANK FUEL SYSTEM Original Filed Aug. 1. 1945 v2 SHEETS-SHEET 2 Jim; E.

IN V EN TOR. 0/? W0 JflN/E IV Patented Sept. 30, 1952 "PCONTINUOUSFFLOWMULTIPLE TANK FUEL ":[SYSTEM 7 [David S amiran', Fort Wayne, Ind.

-r'iginal"applicatio'n August 1,1945, Serial No. ;608,348,1now PatentNo. 2,516,150, ,dated July v 425; 1950.. Divided and'thisapplication-December 23, 1949, Serial No. 134,794

3 Claims; (C1.158-"-36.)I

, )(Granted. under1the act 'of March 3,1883,-;-as

'- I amended April 30, 1928; 370 0. G. 757) I The inventiondescribedherein may be vinan- 'ufactured -and used by ornfori the UnitedStates 7 Government for governmental purposes without payment to me ofany royalty. thereon.

Referringinow toFig. 1 of .thedrawings an aircraft engine IIl'. carriesthe .usual engine: pump I2 which, isoperatively,,-.connected:ftogthez-enginc toibedriven thereby andadapted. to supplyjuel under? pressure; to the carburetor- I4 ortoL-ailike "Ihisv invention relates to an'aircraftfuel sys- 5 fuelmetering-device; A =mainc:t=ank I6 and two tem and is a division of mycopending applica' auxiliary tanks" I8 and 20 are;- provided andxaretionvSerialNo. 608,348,?filedAugust::1, 1945; and normally soxc'onnectedx'thati the :iuel; in fall. of 'now matured.int-o'xPatent No.2,516,150 of July the tanks flows through the-main tank" Iii-to the 25-,1950. suction side of the engine. pump I0.

' 'In modern aircraft, 1 particularly in :warcraft l0 {All electricmotor: driven pumD ZZ; is' arranged it is current practice to carry thefuel in a series I to .pump from theib-ottomi-of the main; tank; I6, ofseparate tanks distributed as uniformly I as through a, pipezzd;selector 26 and pipe 28- to the "practicable throughout the availablespace: in engine pump? I2. The selector 2B is shown in a .the craft,this practice Joeing conducive to unijposition whichconnects the pipe24: tovthe-pipe f rm W i h dis ri iomas' Well as having'the 28, but isrotatable to a positioniwhich connects I advantage that if one tank ispunctured 'and. 'the'pipeiZtl-to" the"pi-pe':'48;-: iWhen the pointer"loses its fuel; the loss Will be proportionallyiless ,knob 25-p0ints totheindi-cium M as shown in asIthe nlllilrtr bler 2f tlanlfrs ilsgreiater. I ,h t f Fig. 1, the tankt I6 is connected, dlirectly,v te1the n m p an 8 S31 em's'as ere o ore suction'sidel-of: heiengine pump2,:and'w en constructed and arranged, a selector c-ock has thep0inter1lkn0bi isturned. ninety degrees usuallyfbeen provided with aposition -f-or:.each anticlockwise-to the cindi-cium A, the auxiliarytankiwhe'reby the pilot p g-thatione tanks: I 8:: and 29 "will beconnected-to the suctank is empty switches the selector to another. tiid ofthe engine pum-p. 1

' T s rran m however, has he isa v The: pressure 'inlets-saend-icc atthe tops of tage that an emergency pump is required-which 25 thepressurizedtanks I8 and 20, respectively, are will D p f l from so e assource Wh connected to 'a pressure source 30- bygpipes 32, thechange-over from one tank to another is c4 and 36.

' being efiected, together with a pressure drop The fueldischargepopenmgs 42 and 44" are sensitive instrument-which will startand stop connected'by piping dfiw and 48 to the'top of the emergencypump as-the pressure situatio I the main :tank' I 6 and. to the selector26' respec- 're%ilires.b t f th t t t ,givelythA' tspriliiglsloadedXalvfeill' att tlinlll'b e o J o e'presen inven ion is o pro- 20f e anconsis s o a sea I an a vide a'multiple ta fuel Sys e pr a valve head'54 adapted'tobe pressed upon the main tank having an electric pump -by:which seat by a spring 56,-whereby, with the same presgf'uel y Pe'p ptly-to the-suction side suretap-plied"atthe-pressure inlet 38 as at the1of i'ilie 61351118 pump .ardid asi1esfoflp1essuizd pres'isulre inleti3Marthe; fuelfnlhthe-tankgmkwil an s w1 means o irec e: ue orce y .be 'ei'vered 0- e opo e main an pressure from the pressurizedtanks into the'before the fuel in the tank I8.

main tank, with automatically selective means A ky a e 53 in the ipe 46is biased to t pty 1 f r ik l 0f g tgp g tanks into prevent returnflowto the auxiliary tanks. A e'mam a 111 a D Sequencefloat valve 60hinged' at 62 Within'the tank I6 I I -Other objects, advantages, andmeritorious revents the pressure source 30 from forcing F W F g i g i ifuel from the auxiliary tanks I8 and 20 into the 15 fur e f W1 referencehe r 5 main tank I6 faster than itis being pumped ut i i g' chemafi'v 1aout of the ed by the electric pump 22; Float valves 64 in the 5 .fuel gr f f is i g of v g 4. bottoms of the, tanks I8 .and ZD 'arearranged toclose thefuel outlets and 44 Where their Fig. 2 is 'a schematic layoutof a fuelsystem respectwe i k empty :similar touFig. 1 but including apair of auxil- The {marathon P the F w-9 f i iary tanks equipped with."spring loadedsoutlet i CY H nf ig my omoperates sub- Like referencecharacters refer; tozlike: parts Withlallitanksffull as shown in F g. 1,the se- -.:.throughoutthe'severalviews. 5 lector mayb ttu'rnedtuthepflsion shown iwith v the pointer knob Z 5 pointing 'to M and. the

3 engine I and the electric motor driven pump 22 started. As fuel ispumped out of the tank I6 by the electric motor drivenpump 22, thefloat.60 drops and allows the pressure source 30 to forcefuel from thetank 20, through pipes 4'6 into the main tank IE to replace that used.No fuel will flow from the tank I8 because of the spring loaded valve 50until all fuel has been forced out of the tank 20 whereupon the floatvalve 64 in the tank 20 will close to prevent air under pressure flowingfrom the'tank 20 to the top of the main tank I6.

As soon, however, as the float valve 64 closes the outlet 44 of the tank20, the valve'50 will open and fuel will be forced from the tank I8 intothe main tank I6 until the tank I0 is empty and its float valve 64closes the fuel outlet. Fuel will now be supplied to the carburetor IA-by the main tank I6 until that is empty.

The operation just described assumes that there has been no combatdamage tothe system. However, should the main tank I6 be damaged or thepressurizing unit 30 fails to function, or

if for any otherreason it became desirable to use the fuel in theauxiliary tanks first, the se lect-or may be turned to the position Aand the fuel may be drawn by the engine pump I2 directly from theauxiliary tanks I8 and 20;

In Fig. 1 there is shown a fuel system havin only two auxiliary fueltanks. vious that one or more auxiliary fuel tanks may be added and thefuel may be fed from them in any desired sequence by providing all butthe first auxiliary tank with spring loaded'outlet valves of graduatedloading so that transfer of fuel therefrom into the main tank I0 willtake place in inverse order of the strength ofthe spring loading of thecheck valves associated with the respective auxiliary fuel tanks. Such afuel system is shown schematically in Fig. 2, the system being like thatof Fig. 1. except for the addition of another auxiliary fuel tank IIB.In Fig. 2 the system includes a main fuel tank II6 connected to theauxiliary fuel tanks H8, H8 and I20 by pipes I46. The auxiliary fueltanks are connected to a pressurizing source I30 by pipes I32, I32, I34and I35. The outlets I42 and I42 of the auxiliary tanks H8 and H8 areprovided with spring loaded valves I50 and I50" having a constructionlike that of valve 50 in Fig. 1. However one valve, such as I50, has astronger spring loading than the other valve, such as I50. Thereforeafter fuel is forced from auxiliary tank I20 by way of outlet I M andafter this tank is emptied, then fuelis fed automatically from auxiliarytank I I8 by way of outlet I 42 and spring loaded valve I50. After tankH8 is emptied, then fuel is fed from auxiliary tank II8 by way of outletI42 and spring loaded valve I50. Thus it will be seen that pressureapplied on the fuel in the auxiliary tanks causes transfer of fuel fromthe auxiliary tank I20 to .the main tank H6 before subsequent transferof fuel from the other auxiliary tanks H8 and H8 to the main tank, withthe subsequent fuel transfer taking place from these other auxiliarytanks in inverse order of the strength of the spring loading of thespring loaded valves I50 and I50 associated with the respectiveauxiliary tanks H8 and I I8.

Having described my invention, I claim:

1. In an aircraft fuel system, a main fuel tank, two auxiliary fueltanks, an outflow pipe for each auxiliary fuel tank extending fromthebottoms of said auxiliary fuel tanks to the outside of said Howeverit is ob'-' auxiliary fuel tanks, conduit means flow-connecting theouter ends of said outflow pipes to thetop of said main fuel tank,,afloat valve near the top of saidmain fuel tank operable to close andprevent "fuel inflow" through" said conduit means into the main fueltank when the fuel in'the main fuel tank rises above a predeter- 'minedlevel and "operable to open and permit fuel inflow through said conduitmeans into the main fuel tank when the fuel in the main fuel tank fallsbelow said predetermined level, a float "of fuel from the otherauxiliary fuel tank to the CJI main fuel tank before the subsequenttransfer of fuel from said one auxiliary fuel tank'to the main fueltank.

2.- In an aircraft fuel system, a main fuel tank. a plurality ofauxiliary fuel tanks, an outflow pipe extending from a point near thebottom of each of the auxiliary fuel tanks upwardly to the outside ofsaid auxiliary fuel tanks, conduit means flow-connecting the outer endsof said outflow pipes to the top of said main fuel tank. valve means forcontrolling fuel inflow through said conduit means into said main fueltank and operable to close when the fuel in the main fuel tankrisesabove a predetermined level and operable to open when the fuel in themain fuel tank falls below said predetermined level, valve means in eachauxiliary fuel tank operable to close and prevent outflow of air throughthe respective outflow pipes when the auxiliary fuel tanks are empty offuel, means for applying equal air pressure to the top surfaces of thefuel in the several auxiliary fuel tanks for transfer ring fuel from theauxiliary fuel tanks into the main fuel tank by way of the outflow pipesand the conduit means, and a check valve in the outflow pipe extendingfrom all but one ofthe auxiliary fuel tanks, whereby said air pressurecauses transfer of fuel from said one auxiliary fuel tank to the mainfuel tank before the subsequent transfer of fuel from the otherauxiliary fuel tanks to the main fuel tank.

3. In an aircraft fuel system, a main fuel tank, a plurality ofauxiliary fuel tanks, an outflow pipe extending from a point near thebottom of each of the auxiliary fuel tanks upwardly to the outside ofsaid auxiliary fuel tanks, conduit means flow-connecting the outer endsof said outflow pipes to the top of said main fuel tank, valve means forcontrolling fuel inflow through said conduit means into said main fueltank and operable to close when the fuel in the main fuel tank risesabove a predetermined level and operable to open when the fuel in themain fuel tank falls below said predetermined level, valve means in eachauxiliary fuel tank operable to close and prevent outflow of air throughthe respective outflow pipes when the auxiliary fuel tanks are empty offuel, means for applying equal air pressure to the top surfacesof-the'fuel in the several auxiliary fuel tanks for transferring fuelfrom the auxiliary fuel tanks into the main fuel tank by way of theoutflow pipes and 5 6 the conduit means, and spring-loaded checkREFERENCES CITED Valves in the 9 Plpes extendmg from P The followingreferences are of record in the but one of the auxiliary fuel tanks andhavin fil f this patent; progressively increasing spring loadingthroughout the several check valves, whereby said air 5 UNITED STATESPATENTS pressure causes transfer of fuel from said one Number Name Dateauxiliary fuel tank to the main fuel tank before 1,367,460 Caudron Feb.1, 1921 the subsequent transfer of fuel from the other 1,407,374Buckend-ale Feb. 21, 1922 auxiliary fuel tanks to the main fuel tankwith 2,389,667 Hudson Nov. 27, 1945 said subsequent transfer takingplace from the 10 2,394,506 Woods Feb. 5, 1946 other auxiliary fueltanks in inverse order of the ,409,245 Black Oct. 15, 1946 strength ofthe spring loading of the check valves FOREIGN PATENTS associated withthe respective auxiliary fuel tanks. Number Country Date DAVID SAMIRAN15 146,446 Great Britain July 3,1920

